Convert Windows Media Video (.wmv) to WebM Video (.webm) online for free. Fast, secure video conversion with no watermarks or registration.
Conversion settings — add a file to adjust
Upload your .wmv file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .webm file when it's ready.
WMV was Microsoft's answer to web video streaming, while WebM is Google's open-source response. WebM uses VP8 or VP9 video codecs (royalty-free) with Vorbis or Opus audio in a Matroska-derived container. WebM is natively supported in Chrome, Firefox, Edge, Opera, and Safari (since Big Sur), making it the standard for patent-free HTML5 video. VP9 achieves compression on par with H.265 — roughly 30–50% more efficient than H.264. Converting WMV to WebM modernizes Microsoft's legacy format for today's web.
WMV cannot play in any web browser natively — Flash and Silverlight, which once provided WMV web playback, are both discontinued. WebM provides native <video> element support in all modern browsers without plugins. If you are publishing video on the web, WebM with VP9 and Opus delivers the best compression available in a royalty-free format, reducing bandwidth costs and improving load times.
FFmpeg decodes VC-1/WMV2 video and WMA audio, then re-encodes video to VP9 using libvpx-vp9 and audio to Opus using libopus. VP9 encoding supports CRF mode (recommended: CRF 30–35 for web, 23–28 for high quality) and two-pass encoding for optimal bitrate allocation. The WebM container includes cue points for seeking. VP9 is significantly slower to encode than H.264 but produces smaller files at equal quality.
VP9 at CRF 31 matches H.264 at CRF 23 in visual quality but produces roughly 30% smaller files. Opus audio at 128 kbps is transparent for music and speech. The main tradeoff is encoding time — VP9 takes 3–10x longer than H.264 to encode, but the result is ideal for web delivery where files are encoded once and served millions of times.
| Device | WMV | WebM |
|---|---|---|
| Windows PC | Native | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Native |
| Linux | Partial | Native |
| Web Browser | No |
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
WMV to WebM conversion modernizes legacy Windows Media content for the web. VP9's efficient compression and universal browser support make WebM the premier format for HTML5 video delivery.
安全な転送
HTTPS暗号化アップロード
プライバシー優先
処理後にファイルを自動削除
登録不要
すぐに変換を開始
どこでも動作
あらゆるブラウザ、あらゆるデバイス
| Native |
| 特徴 | WMV | WebM |
|---|---|---|
| 正式名称 | Windows Media Video | WebM Video |
| 拡張子 | .wmv | .webm |
| 最適な用途 | Windows native | Web optimized |